CAIRO (AP) — Tens of thousands of Islamists and young activists massed Friday in Tahrir Square, confronting Egypt’s ruling military council with the largest crowd in months to protest the generals’ attempt to give themselves special powers over a future elected government.

While united against the army, however, conservatives and liberals were jockeying among themselves for votes in crucial parliamentary elections only 10 days away.

The stakes are higher for all sides than at any time since the uprising ousted President Hosni Mubarak in February. The victors will help choose who will draft a new constitution, thus defining the character of post-revolutionary Egypt.

Most of this year’s rallies in Tahrir Square since Mubarak’s ouster have been led by liberal- or left-leaning groups, but Islamists dominated Friday’s protest. Members of the Muslim Brotherhood, Egypt’s best-organized group, carried signs and waved flags bearing the logo of its Freedom and Justice party. Elsewhere, ultraconservative Salafis in long robes and bushy beards called for application of Islamic Sharia law.

For most of the day, liberal groups showed little organized presence.

The mobilization by the Brotherhood, which had until recently avoided confrontation with the ruling Supreme Council of the Armed Forces, reflects a shift in the group’s position. It has threatened to escalate its protest campaign if plans to give permanent political powers to the military are not scrapped.

“The army has no role in ruling people,” said Hani Hegazi, who came by bus from outside Cairo with other Brotherhood members. “Its only job is to protect the country. We want civilian rule chosen through democracy.”

Other protesters carried banners reading “Down with military rule. Egypt our country is not a military camp.” Many had Egyptian flags, while some religious conservatives waved flags calling the Quran, Islam’s holy book, “our constitution.”

The rally’s primary target was a document floated by the government that declares the military to be the guardian of “constitutional legitimacy,” suggesting it would have the final word on major policies, and possibly legislation, even after a new president is elected.

The document, meant to spell out guiding principles for the new constitution, would shield the military and its budget from civilian oversight. An early version of it also said the military would appoint 80 members of the 100-person constitutional committee — a move that would vastly diminish the new parliament’s role.

Groups across the political spectrum rejected the document, calling it an attempt by the military to perpetuate its rule past the post-Mubarak transition period. The Brotherhood has said the document “reinforces dictatorship,” and last-minute negotiations between the government and the Brotherhood failed to break the impasse.

“All of us are scared that the army could try to hold on to power,” said Walid Farouq, 32, who wore the long beard and traditional robe of ultraconservative Muslims. “It is time for a civilian government.”

Anger has been building against the generals, whom many accuse of using Mubarak-era tactics to crack down on critics, failing to reform the security forces and monopolizing decision-making. Many fear the generals will seek to retain their power — a claim they deny.

The military originally promised to transfer power to an elected civilian government within six months of Mubarak’s ouster. But a vague, new timetable suggests that presidential elections won’t be held until 2013. Specific dates have only been set for parliamentary balloting, set to begin Nov. 28 and drag into March.

Field Marshal Hussein Tantawi, Egypt’s military ruler, fueled speculation he might seek the presidency when he strolled through downtown Cairo in September in civilian attire, shaking hands and patting shoulders. The military has denied it has any intention of staying in power or fielding its own candidate in a presidential election.

The show of force by Islamist groups comes 10 days before the first of six rounds of voting. The Brotherhood’s Freedom and Justice party, expected to take the most seats in the election, was well-represented at Friday’s rally. Others bore banners for the Salafi al-Nour party.

The sudden prominence of such groups, which either avoided politics or organized in secret to avoid crackdowns under Mubarak, has frightened some liberals, who fear an Islamist-dominated parliament will inject too much religion into the constitution.

“Lots of people are scared of the Islamists,” said Mahmoud Abdel-Rahman, a liberal university student who came from the coastal city of Alexandria for Friday’s rally.

As he spoke, dozen of bearded men walked by, chanting, “The people want to apply God’s law!” — an Islamist twist on the uprising’s rallying cry, “The people want to topple the regime.”

“But they’re not using language that brings people together, so only people like them will vote for them,” he said. “It’s clear that they can get people out in the street, but can they also get people to vote for them? We’ll have to wait and see.”

Protesters also celebrated the 30th birthday Friday of blogger Alaa Abdel-Fattah, one of the most prominent revolutionaries to be jailed by the military prosecutor. Abdel-Fattah’s mother, who has been on hunger strike for 13 days, and his wife, pregnant with the couple’s first child, unveiled a large birthday cake with the blogger’s image on it.

Abdel-Fattah was detained after refusing to answer questions from a military prosecutor about his alleged role in sectarian clashes that killed 27 people, most of them Christians.

Many blamed the military for the violence, and saw Abdel-Fattah’s detention as an attempt to smear prominent activists.